TDuring an exciting and lively first set during what would have been the last singles match of her career, Serena Williams Staring at the world’s No. 2 player, Annette Kontaveit, she responded to her challenge with an excellent performance. In the second set, she was barely holding on. When she saved a 1-3 break point with a sweet ace, she raised her hands to the sky, angry that she couldn’t find that shot every time she served.

If this was any other 40-year-old girl in tennis history, with the one-year suspension rusting and nerves from her last event, such deficiencies would have been expected. But this is Serena Williams. Not only did she adhere to stratospheric standards, but she did so fully during the raving second night of her stay at Arthur Ashe Stadium. In defeating Kontaveit, she postponed her solo retirement for another tour by producing at least one legendary moment in a career filled with them.

After her opening round win gala, with her in-court celebration and Billie Jean King speech, the second round felt different. The crowd was much more silent, not just there to say goodbye, while Williams focused on the laser. Locked in immediately during the first high-intensity set, one filled with good shots from both but dominated by Williams’ serve – she is still, at 40, the best server in the world. Under throttle pressure, I closed the tiebreak as I had done many times over the years – a non-rebound serve followed by an ace.

To her credit, Kontaveit played an impeccable second set, flashing winners from both flanks and kissing streaks, but Williams responded simply by raising her level and managing the match very well at closing. By the final matches, she had completely taken control of the baseline and eliminated Kontaveit’s serve until the end.

It’s a remarkable achievement given its limitations. Her first send was amazing, but she averaged just 99 mph in the first set — she hadn’t served much under pressure last year, so she was initially very cautious, prioritizing accuracy and percentage over power. Her movement, which is historically one of her greatest assets, has diminished significantly, but she still found a way out of a run of 19 strokes in depth in the third set when she needed it most. Despite her lack of match fitness, she was a rock in the defining moments.

Over the course of two hours and 27 minutes on the court, she played all the hits at least one more time: aces and fierce winners she kept for important points, roars and pains alike, laying her heart on her diamond-encrusted sleeves. Halfway through the third set, Williams was frustrated by the electronic line connection and told referee Allison Hughes. Then she returned to baseline and channeled her anger into winning tennis.

It was especially amazing considering how far from this look she has looked since her comeback. Williams lost in the first round of Wimbledon, was easily eliminated by Belinda Bencic in Toronto, then lost 6-4 6-0 to Emma Radocano in Cincinnati. She described the last weeks of her career as very difficult.

Williams arrives in New York low-confidence but with one last chance to make any impression in the final phase of her career, and there are no more chances of redemption. The pressure could have been stifling, but, as she has done so many times in her career, she rose to the occasion. Her success stemmed from seeing her eventual heroism as a reward rather than the burden it could have been. “I’ve had a big red X on my back since I won the US Open in ’99,” she said. “She’s been there all my career, because I won my first major early in my career. But it’s different here. I feel like I’ve already won.”

She finished the match with a booming backhand, tore Kontaveit in the final and sealed her victory with a winning backhand. As former player Mary Jo Fernandez dictated the interview in court, her presence alone was a reminder of Williams’ ridiculous longevity. Fernandez is 51 and has been retired for 22 years, but she and Williams were rivals in 1999. I asked Williams if she was surprised by her level on the court, to a giggle and a heavy stare. “I’m just Serena,” she said.

On Thursday night, Williams will return to the same spot, at the same time as her sister Venus, as they compete together in doubles for the last time, a scene that may be more emotional and fundamental than singles. Then she will face Australian Aja Tomljanovic on Friday. This could be the night you say your last goodbye, or the next step on one last legendary run. Regardless, Wednesday night, I gave the world at least one final show of the unforgettable scene of Serena Williams in full flow.